1. Field of the invention
The invention relates to a system enabling use of GSM mobile telephones in a DECT mobile telephone network. A DECT mobile telephone network is conventionally used to enable employees of a business to use the services of a private automatic branch exchange with the benefit of some degree of mobility within the site of the business. A network of this kind includes a private automatic branch exchange, transceiver stations referred to as DECT base stations, DECT mobile telephone terminals and possibly fixed telephone terminals.
2. Description of the prior art
A network of the above kind enables some mobility of employees within the premises on a site of the business. Some employees are required to leave the site, however. To be able to be reached virtually wherever they are, each carries a GSM mobile telephone terminal with a subscription to a GSM public network. They are therefore required to use at least two types of terminal according to whether they are on a site of the business or off the site.
The multiplicity of terminals for the same employee is not practicable, in particular because of the multiplicity of numbers. Also, employees are tempted to use only their GSM terminal, although calls then cost more than calls via the DECT private network and even though the GSM public network does not provide all the services that can be obtained from the private automatic branch exchange of a business. Furthermore, users outside a business are tempted to call the employees of the business via their GSM terminals, and not via the fixed or DECT terminals, to maximize the chances of reaching them. It is therefore desirable for the employees of a business to be able to use their GSM terminals via the private network of the business.
The object of the invention is to enable the employees of a business to use their GSM terminals within the business at the same cost and with the same services as if they were DECT terminals and to enable properly authorized outside visitors to use their GSM terminals as DECT terminals of the business, to access the fixed public network via the private automatic branch exchange of the business, or to be called via the fixed public network.
In a first aspect, the invention provides a system enabling use of mobile telephone terminals to a first standard in a private telecommunication network to a second standard, the private network including:
at least one private automatic branch exchange,
mobile telephone terminals to the second standard,
base stations to the second standard having input-output ports connected to input-output ports of the private automatic branch exchange, the input-output ports having an interface specific to the base stations;
which system includes a radio transceiver to the first standard, a radio transceiver to the second standard and a converter for carrying out:
a declaration and location procedure in the private network for terminals to the first standard; and
conversion between a signaling protocol to the first standard and a signaling protocol accepted by the private automatic branch exchange.
In a second aspect, the invention provides a system enabling use of mobile telephone terminals to a first standard in a private telecommunication network to a second standard, the network including:
at least one private automatic exchange,
mobile telephone terminals to the second standard,
base stations to the second standard having input-output ports connected to input-output ports of the private automatic branch exchange, the input-output ports having an interface specific to the base stations to the second standard;
which system includes a radio transceiver to the first standard, a cable link to a private automatic branch exchange of the private network and a converter for carrying out:
a declaration and location procedure in the private network for terminals to the first standard, and
conversion between the signaling protocol to the first standard and a signaling protocol accepted by the private automatic branch exchange.
The above systems are seen as base stations to the first standard by the terminals to the first standard and each is seen as n terminals to the second standard by the private network if there are n terminals to the first standard communicating with one of the systems.